index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="style.css">
    <title>Document</title>
</head>
<body>
    <div class="conteiner">
        <div class="menu">
            <div id="inputName">
                <p>
                    <b>Your name:</b>
                    <input type="text" size="40" id="name">
                </p>
                <button onclick="document.location='game.html'">Continue</button>
            </div>
            <div class="main">
                <div class="logo">
                    <h1>DragonBorn</h1>
                </div>
                <div class="btn">
                    <div class="start">
                        <button id="show">Start</button>
                    </div>
                    <div class="inst">
                        <button onclick="document.location='instruction.html'">Instructions</button>
                    </div>
                </div>
            </div>
        </div>
    </div>
    <script>
        let show = document.getElementById("show");
        let inputName = document.getElementById("inputName");

        show.addEventListener("click", () => {
            inputName.style.display = "block";
        })
    </script>
</body>
</html>